Zan Lingxing, Xing Da, Abd-El-Latif Abdelaziz Ali, Baltruschat Helmut
Institut für Physikalische und Theoretische Chemie, Universität Bonn, Römerstraße 164, D-53117 Bonn, Germany.
Key Laboratory of Chemical Reaction Engineering of Shaanxi Province, College of Chemistry & Chemical Engineering, Yan'an University, Yan'an, 716000 P.R. China.
Beilstein J Nanotechnol. 2019 Dec 18;10:2541-2552. doi: 10.3762/bjnano.10.245. eCollection 2019.
Magnesium-based secondary batteries have been regarded as a viable alternative to the immensely popular Li-ion systems owing to their high volumetric capacity. One of the largest challenges is the selection of Mg anode material since the insertion/extraction processes are kinetically slow because of the large ionic radius and high charge density of Mg compared with Li. In this work, we prepared very thin films of Sb by electrodeposition on a Au(111) substrate. Monolayer and multilayer deposition (up to 20 monolayers) were characterized by cyclic voltammetry (CV) and scanning tunneling microscopy (STM). Monolayer deposition results in a characteristic row structure; the monolayer is commensurate in one dimension, but not in the other. The row structure is to some extent maintained after deposition of further layers. After dissolution of the Sb multilayers the substrate is roughened on the atomic scale due to alloy formation, as demonstrated by CV and STM. Further multilayer deposition correspondingly leads to a rough deposit with protrusions of up to 3 nm. The cyclic voltammogram for Mg insertion/de-insertion from MgCl/AlCl/tetraglyme (MACC/TG) electrolyte into/from a Sb-modified electrode shows a positive shift (400 mV) of the onset potential of Mg deposition compared to that of a bare Au electrode. From the charge of the Mg deposition, we find that the ratio of Mg to Sb is 1:1, which is somewhat less than expected for the MgSb alloy.
由于镁基二次电池具有高体积容量，它被视为极受欢迎的锂离子系统的一种可行替代方案。最大的挑战之一是镁负极材料的选择，因为与锂相比，镁的离子半径大且电荷密度高，其嵌入/脱出过程在动力学上较为缓慢。在这项工作中，我们通过电沉积在Au(111)衬底上制备了非常薄的锑薄膜。通过循环伏安法（CV）和扫描隧道显微镜（STM）对单层和多层沉积（多达20层）进行了表征。单层沉积会产生一种特征性的行结构；该单层在一个维度上是相称的，但在另一个维度上则不然。在进一步沉积多层后，行结构在一定程度上得以保留。锑多层膜溶解后，由于合金形成，衬底在原子尺度上变得粗糙，CV和STM证明了这一点。进一步的多层沉积相应地导致形成有高达3纳米凸起的粗糙沉积物。从MgCl/AlCl/四甘醇二甲醚（MACC/TG）电解液中镁嵌入/脱出到锑修饰电极以及从锑修饰电极中脱出镁的循环伏安图显示，与裸金电极相比，镁沉积起始电位正移了400 mV。从镁沉积的电荷量来看，我们发现镁与锑的比例为1:1，这略低于MgSb合金的预期比例。
